Draftsman&#39;s template



2, 1949. c. s. AGRILLO 2,478,071

DRAFTSMAHS TEMPLATE Filed July so, 1946 2 Sheets-Sheet 1 INVENTOR.

BY [ma .5: 3405/;14

ATTORNEYS 1949. c. s. AGRILLO 2,478,071

I DRAFTSMANS TEMPLATE Filed July 30, 1946 2 Sheets-Sheet 2 INVENTOR.

Patented Aug. 2, 1949 UNITED STATES PATENT OFFICE DRAFTSMANS TEMPLATECharles S. Agrillo, Watertown, Mass.

Application July 30, 1946, Serial No. 687,108

4 Claims.

My present invention relates to a template for use in drawing arcs as,for example, in highway layout work and in drafting in order that thedraftsman may have a single, convenient instrument that may be easilyand accurately used in drawing arcs of substantial length and entirecircles, if desired, of a substantial range of radii.

In many instances, arcs and circles of difierent radii have to be sofrequently drawn that some instrument is required to expedite thedraftmans work. While templates have been proposed, these have not beensufficiently practical to replace the curves commonly used. Such curvesenable an arc to be drawn, but are objectionable because of the numberof curves required to give the desired range and because of theinconvenience incidental to their use.

In accordance with my invention, I provide a template consisting of abody, preferably of transparent stock, having a plurality of concentricarcuate slots extending therethrough. The width of each of the slots isequal to a predetermined unit of measurement and the slots arepreferably uniformly spaced from each other. I provide the body with aplurality of ar-cuate indicia, pairs of which are spaced apart adistance equal to the unit of measurement and which extend from one endto the other of each slot substantially in alinement with its inner andouter edges. Preferably, the slots are slightly wider than said unit inorder that arcs drawn along their inner and outer edges will registerwith the corresponding indicia and be spaced apart a distance equal tothat unit.

In the preferred embodiment of my invention, the slots are alternatelydisposed on opposite sides of a diameter so that while two sets of slotsare established, the slots of each set are spaced apart a substantialdistance. This fact, together with the fact that the adjacent ends ofthe slots of each set terminate short of each other ensures rigidity ofthe template and accuracy in its use.

In the accompanying drawings I have shown illustrative embodiments of myinvention from which these and other novel features and advantages of myinvention will be readily apparent.

In the drawings:

Fig. 1 is a plan view of a template in accordance with my invention.

Fig. 2 is a section along the lines 2-2 of Fig. 1.

Fig. 3 shows another embodiment of my invention, and

Fig. 4 is a section along the lines 4-4 of Fig. 3.

In the embodiment of my invention shown in Figs. 1 and 2, I haveindicated generally at ID a body which may most conveniently be of atransparent plastic or other transparent material and which is shaped toestablish a base ll having a straight bottom edge I? and a semi-circularprojection l3 intermediate the ends of its upper edge therebyestablishing shoulders I 4 and I5 which define a diameter disposeddiagonally with respect to the straight edge l2 of the base I i.

I form the body with a plurality of slots is which are arcuate withrespect to the center ll of the projection l3. The slots '6 are of thesame width and are preferably uniformly spaced from each other. The bodyl0 also has pairs of arcuate indicia, shown as grooves l8 extending fromone end to the other of each slot and substantially in alinement withits inner and outer edges. The grooves [8 of each pair are spaced fromeach other by a predetermined unit of measurement and the pairs ofgrooves are preferably spaced from each other a like distance. In thedrawings, the grooves are shown as being spaced 4 inch from each other.In practice, the slots i 6 are slightly wider to permit an arc to bedrawn along either its inner or its outer edge that is in alinement withthe corresponding groove associated therewith.

I have shown the slots 56 as alternately arranged on opposite sides ofthe diameter l9 established by the shoulders l4 and I5 so that two setsof slots are established with the slots of each set being wholly locatedon one side of that diameter. By this arrangement, I am able to providea template in which the slots of each set are separated from each otherby a multiple of the distance between the indicia so that a suflicientamount of stock is available to ensure that the template is sufilcientlyrigid for accurate use.

It is, of course, desirable to have the slots as long as possible and Ihave found that they may be in the order of 165 without weakening thetemplate. In practice, I prefer that the adjacent ends of the slots ofboth sets be spaced from each other. In practice, these are spacedsubstantially 15 apart with their extremities spaced substantially 7 /2"from the diameter I9. One set of opposite ends of the slots of both setsdefine a diameter 20 in parallel with the straight edge I! while theother set of opposite slot ends define a diameter 2|. By thisconstruction, I provide adequate stock between the adjacent ends of eachset of grooves to further ensure that my template is suitably rigid.

The base I I may be provided with other indicia, useful to thedraftsman, such as the set of holes 22 which enable complete circles ofrelatively small diameter to be drawn.

In Figs. 3 and 4, I have shown a modification of my invention in whichthe body 23 has a base 24 having a bottom straight edge 25 and asemicircular projection 26 intermediate the ends of its upper edgethereby establishing shoulders 21 and 28.

The body 23 has a set of slots 29 arcuate with respect to the center 30of the projection 26. The body 23 also has pairs of arcuate indicia inthe form of grooves 3| which are of a predetermined width and which arespaced uniformly from each other. A pair of grooves extends from one endof each slot to the other substantially in alinement with its inner andouter edges and preferably the width of each slot is slightly increasedto enable a line drawn along either edge to register accurately with thecorresponding groove associated therewith. The base 24 is also providedwith a set of holes 32 for use in drawing complete circles of varioussmall diameters. v

A template in accordance with my invention is easy to use and enablesthe draftsman to do his work with increased accuracy and convenience. Heis able to draw an arc of substantial length without repositioning mytemplate and should it be necessary to increase its length to a fullcircle, the template may be accurately repositioned because of thearcuate indicia associated with each slot which may be easily andaccurately disposed in registry with a completed arc. The centers enablecenter points on the Work to be accurately located and while I provide asufficient number of slots so that arcs of a wide range of radii areavilable, my template is compact and rigid enabling arcs to be quicklyand easily drawn so that the draftsman has available at all times asingle instrument which eliminates the inconvenience of having tomaintain a substantial number of curves on hand.

What I therefore claim and desire to secureby Letters Patent is:

1. A template comprising a body of transparent stock having a pluralityof concentric arcuate slots extending through said body, said slotsbeing radially spaced from each other, and said body having a pluralityof concentric arcuate lines, pairs of which are spaced apart and extendfrom one end of each slot to the other end thereof substantially inalinement with its inner and outer edges.

2. A template comprising a body of transparent stock having a pluralityof concentric arcuate slots extending through said body. the width ofeach slot being such that arcs drawn along its inner and outer edges areradially spaced apart by a predetermined unit of measurement, said slotsbeing uniformly radially spaced from each other, and said body having aplurality of concentric arcuate lines, pairs of which are spaced apart adistance equal to said unit and extending from one end of each slot tothe other end thereofi and being spaced relative to its inner and cute,edges so that a line registers with a line drawnl along either edgethereof.

3. A template comprising a body of transparent stock having a pluralityof concentric arcuate slots extending through said body and spacedradially uniformly from each other but being alternately disposed onopposite sides of a diameter so that two series of slots areestablished, and said body having a plurality of pairs of concentricarcuate lines, each pair of which extends from one end of a slot to theother end thereof substantially in alinement with its inner and outeredges.

4. A template comprising a body of transparent stock having a pluralityof concentric arcuate slots extending through said body and spacedradially uniformly from each other but being alternately disposed onopposite sides of a diameter so that two series of slots areestablished, said slots being of such a width that arcs drawn along theinner and outer edges of any slot are spaced apart by a predeterminedunit of measurement, and said body having a plurality of pairs ofconcentric arcuate lines, each pair of which extends from one end of aslot to the other end thereof and is spaced relative to its inner andouter edges to establish a continuation of a line drawn along either ofsaid edges, whereby the slots are successively spaced from each other adistance related to said unit and the slots in each series aresuccessively spaced apart by a multiple thereof.

CHARLES S. AGRILLO.

REFERENCES CITED UNITED STATES PATENTS Name Date Lipke Oct. 26, 1926Number

